Machine for raising areas on printing plates



" 'Oct. 30, 1934. 1. TORNBERG 1,978,972

MACHINE FOR RAISING- AREAS ON PRINTING PLATES Original Filed May 12,1931 2 SheetsSheet 1 6/ QWM C-IM.

Oct. 30, 1934.

Original Filed May 12, 1931 2 Sheets-Sheet 2 Wes/afar 6501" Tar/way 4,7w! I W M NNV Patented Oct. 30, 1934 UNITED STATES PATENT OFFICE MACHINEFOR RAISING AREAS ON PRINTING PLATES Application May 12, 1931, SerialNo. 536,720 Renewed April 4, 1934 6' Claims.

-In the manufacture of printing plates it is very difiicult to provide aplate with a means that will emphasize certain characters or parts ofthe printed page without considerable manual and time-consuming work onthe part of the operator. Atthe present time, where it is desired tobring out, more fully than a printing plate otherwise would, somefeature of the printing plate, this is accomplished by an operationcalled bumping.

An elaborate but crude set of tools is used whereby those-portions ofthe plate to be emphasized are 'p'eened up slightly above the typelevel. The object of this invention is to provide a machine-in whichthis bumping or peening may be done in a simple, easy and uniform mannerwithout involving so much chance of error and with the saving of amaterial amount of time; also to provide a machine-in which a cylinderis mounted in such a way that itcan be turned at will to bring any partof its surface to the top, said cylinder carrying the printing plate tobe operated upon; to provide the cylinder'with means operatedfrom'within for performing the bumping operation and'to provide meanslocated on the outside of the plate and always in alignment with thebumping means inside for supporting the printing surface 'of the plateand cushioning and confining the bumping action.

' Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which Fig. l isa longitudinal diametrical cross section of a machine comprising apreferred embodiment .35 of this invention, showing it in position toact on a plate;

Fig. 2 is an end view of the same; 1 Fig. 3 is an enlarged section, likea part of Fig.

1 showing the anvil in position, and

Fig. l is a similar view showing the operation of the bumping devicepneumatically. For the above mentioned purposes, a frame 10 is:provided, having bearings in which are supported the hubs 11 of acylinder 12. This cylinder is free-to be turned by hand in the hearingsto bring any part of the cylinder to the top. The cylinder carries adetachable end13 on which one of the hubs 11 is fixed. On the cylinderis mounted one or more stationary beveled clamps 14 for one end of theprinting plate 1? and at the other end is a movable clamp' 15 for theother end of the plate. The clamp 15 is operated by a screw 16 and handwheel 17 having its bearing in the end plate 13. V

r The end plate 13 carries a projection 18 on which is pivoted a handle19 by means of a pin 20. This handle or pin carries a toe 21 fitting innotches 22 provided in the top of the frame 10. This positioning deviceis provided to make the operation easier by holding the cylinder in adefinrilte position circumierentially after being placed t ere.

It will be understood that the printing plate P is preferablysemi-cylindrical, such as is commonly used in the newspaper printingart, but the principle can be applied to other types of plates.

In the hubs 11 of the cylinder 12 is journaled a shaft 23, this shaftbeing slidably mounted in these bearings so that it can be moved backand forth and turned circumferentially. On the shaft is pinned a motorbase 24 having a counterweight 25 for holding the motor 26, carried ontop of the base 24, always at the highest point wherever the shaft isturned. At the end of the shaft 23 is a locating and operating arm 27,the end of which is always located over some part of the printing plate.The end is provided with a backing plug or anvil 28 movably mounted.This anvil carries, secured to it, a semi-resilient washer 29 which maybe of cork, leather or a rubber composition that will not be too soft.The anvil 24 is carried on a radially slidable stud 30 having pinned tothe upper end a handle 31. A spring 32 is provided for holding theseparts up in the position shown in Fig. l. The handle may be pressed downto bring the washer 29 into contact with the plate P where it willsteady the plate against blows imparted to it and also will localize thepeening action to the section directly under this washer.

It will be obvious that by turning the locating arm 27 and moving itback and forth, this anvil can be located over any desired part of theprinting plate to provide for the projection of that part from withinagainst the washer 29. This washer will yield enough to allow the plateto push up slightly but being backed up by a metal part and having onlya semi-resilient character it will not yield materially or allow theraising or bumping effect to spread. The peening action is intended onlyfor bringing the desired printing surface out sharply in the print andnot preventing a good print being made from the rest of the plate.

As the handle 31 is forced down a contact ring 33 is brought intoaposition to connect two brushes 34 with each other electrically. Thesebrushes are connected by wires 35 with the motor 26 and start it up.

,ably is integral therewith. A hammer head 42 is slidably mounted in thecross head 40. It is limited in its endwise motion therein by a pin- 43operating in a slot 44 in the cross head. A spring 45 above the horn4lnormally holds the head 42 in its outermost position and. provides ayielding connection in the motion. It will be seen that the rotation ofthe shaft of. the motorcauses, through this chain of connections, thestriker or hammer 42 to deliver blows upwardly.

The part of the cylinder over which the plate P is located is providedwith a series of small radial plungers 46 and in fact the surface of thecylinder within this area is literallycovered with these tplungerslocated as, near together as possible for acting against the bottom sideof the printing plate which is clamped upon it. Each plunger 46 isarranged radially and provided with a spring 47 to return it to a'pointat a distance from the plate and a collar 48 against which the springacts? These plungers otherwise are free to move in accordance with theaction of the hammer 42.

The resultof the operation will be obvious from an inspection of Fig. 3.Of course, it will be understood that the axis of the cross head 40 isalways inv alignment with: the axis of the slidable studBO and that,however the locating arm' is placed, the motor moves around with iteither longitudinally or circumferentially andthese two parts are alwaysin alignment.

Itgwill be seen that-the operator, by grasping the handle 3 may move thelocating device circumferentially and longitudinally along the plate. Hehas the anvil 2-8 and washer 29'right before him so that he can placethem against the surface to be projected or bumped and is sure that theoperation will take place in exactly the right spot. The action ofpushing down. the handle 31 operates the motor as long as this handle isleft down and one or more blows may be imparted to the plate to push itssurface outwardly.

Referring to the handle 19 and notches 22, it willbeseenlfrom Fig. 2that three of these notches are shown. If the operator is working in thecentral portion of the plate, the cylinder is positioned as shown.therein. When he has to work on the left hand part of the plate, thehandle 19 is disengaged from the notch and the cylinder moved to'theright and. the projection 21 engaged in the right hand notch. Thisbrings the left hand part of the plate on: the-top where he canisee itto work Fig. 4 simply shows the same mechanism with a pneumatic hammer50 supplied with air, or any fluid under pressure, through a pipe 51 andoperating substantially in the same way. No further details of thisconstruction are shown as 'theusual elements employed in a pneumatichammer are also employed here.

.Although I'have illustrated and described only twoforms of theinvention I am aware of the fact that other modifications can be madetherein by any person skilled in the art without de- 1. In a device forraising part of the surface of a stereotype printing plate, thecombination of a cylinder mounted to be freely rotatable, means on thecylinder for holding a printing plate thereon, the surface ofthe-cylinder under the printing plate being provided throughout with aseries of small plungers, a shaft on the cylinder free to rotateindependently of the cylinder, a hammer head radially and reciprocablycarried by said shaft inside the cylinder, an arm fixed to said shaftand projecting over the outside of the printing plate, and an anvilcarried by said arm in radial alignment with said hammerhead'.

2. In a device for'raising portions of the printing surface of aprinting plate, the combination of a cylinder, means on the cylinder forsupporting a printing plate to be operated upon, the entire surface ofthe cylinder under the printing plate being provided with a series ofsmall radial plungers, a shaft passing into the cylinder axially andfree to turnwith respect thereto, an armon the shaft extending overtheplate, an, anvil on the arm having a semi-resilientsurface adapted to beheld against the part of the type'surfaceto be raised, a hammer movableradially in the cylinder and in alignment with said anvil, and means forreciprocating said hammer to engage the plunger that is in line with thehammer and anvilto force the plate outwardly against the anvilthroughout the area of the plunger.

3. In a machine for raising an area of a stereotype printing plate, thecombination with a cylinder having means for supporting a curvedstereotype plate, radial plungers carried by the cylinder under theplate, a shaft I extending through the cylinder and rotatable andslidable therein, a frame on the shaft in the cylindercomprising acounterweight, a motor on the frame, means operated by the motor forengaging one of the plungers and forcing theplateout thereby, and meanson the outside of the cylinder for engaging the plate to receive theblows.

4.111 a machine for projecting the area of printing surfaces, thecombination of. a cylinder mounted to be turned freely in its bearings,

means adaptedto be set in different positions for holding the cylinderagainst turning, means on the cylinder for supporting a. printing plateto be operated upon, the area under the plate being filled with a seriesof radial plungers adapted to engage the rear surface of the plate, ashaft extending into the cylinder, movable axially and rotatable, byhand, independently of the cylinder, an anvil-having a semi-resilientsurface at the inner end adapted to engage the type surface, a motorfixed on said shaft inside thecylinder, electric connections. forstarting the motonand means operated by the motor for delivering blowson the rear end of one of said plungers which is in radial alignmentwith the anvil.

5. In a machine for projecting the area of printing surfaces, thecombination of a cylinder,

plate to be operated upon, the area under the plate being filled withlaseries of radial plungers adapted to engage the rear surface of theplate, a shaft extending into the cylinder, movable axially androtatable, by hand, independently of the cylinder, an arm on theshaftoutside, a radially slidable stud on the arm, an anvil having asemi-resilient surface at the-inner end adapted to engage the typesurface, ahandle connected with the stud for moving the anvil intoengagement with the type surface, an electric contact -means on thecylinder for supporting a printing arranged to be closed by the movementof said stud, a motor fixed on said shaft inside the cylinder, wherebythe motor will be started and kept going as long as the stud isdepressed, and means operated by the motor for delivering blows on therear end of one of said plungers which is in radial alignment with theanvil.

6. In a device for raising part of the surface of a stereotype printingplate, the combination of a support mounted to be freely moved, means

